#!/bin/bash
# Host-side C compiler wrapper for the aarch64 cross image (ci/rust-ci-arm64cross.Dockerfile).
#
# Why this exists: ffmpeg-sys-next's build script compiles a probe it intends to RUN — it
# executes the binary to read the libav* version macros — so it forces `.target(HOST)` with
# the comment "don't cross-compile this", but still hands that host compile the TARGET's
# pkg-config include paths. `-I/usr/include/aarch64-linux-gnu` then shadows the host's own
# multiarch libc headers and the x86 compiler dies inside bits/math-vector.h on NEON/SVE
# types it has never heard of.
#
# Prepending the host's multiarch dir does NOT fix it: GCC drops a `-I` that duplicates a
# directory already on its system include path (keeping it in the original, later position),
# so the arm64 dir stays in front. The reliable fix is to remove the target include dirs from
# the host compile entirely — the probe only wants FFmpeg's version macros, and the amd64
# libav*-dev headers are installed and on the default search path, at the same version (both
# come from this Ubuntu release).
#
# Scope: only ever invoked as CC for the HOST triple (CC_x86_64_unknown_linux_gnu). Target
# compiles go to aarch64-linux-gnu-gcc and never pass through here.
set -euo pipefail

declare -a out=()
while (($#)); do
  case "$1" in
  # `-I dir` as two arguments — the form cc's Command building and ffmpeg-sys both emit.
  -I)
    if [[ ${2-} == *aarch64-linux-gnu* ]]; then
      shift 2
      continue
    fi
    out+=("$1" "${2-}")
    shift 2
    ;;
  # `-Idir` glued into one argument.
  -I*aarch64-linux-gnu*)
    shift
    ;;
  *)
    out+=("$1")
    shift
    ;;
  esac
done

exec /usr/bin/cc "${out[@]}"